1. Field of the Invention
The present invention relates to a battery mounting structure in a power-assisted bicycle, and more particularly to a battery mounting structure capable of securely and easily detachably holding a battery.
2. Background Art
A battery mounted on a power-assisted bicycle must be firmly fixed so as not to be easily separated from the bicycle frame during travel over rough roads or when the bicycle falls over. In addition, the battery should be theft resistant. However, it is also desirable that the battery be easily detachable from and attachable to the bicycle frame for recharging.
A conventional battery mounting structure in a power-assisted bicycle is described in Japanese Patent No. 262305. In this mounting structure, a clamp mechanism is provided on a battery case, and a bicycle frame has a shape corresponding to the battery case having external electrodes. Thus, the battery case is fixed to the bicycle frame using the clamp mechanism.
It is desirable to provide a power-assisted bicycle which is both versatile and inexpensive, by mounting a power unit and a battery on an existing bicycle frame without extensively changing the design of the existing bicycle frame. This modification also requires the introduction of the assist power into the chain line.
However, the bicycle frame in the above patent must have a shape corresponding to the battery case, and an existing bicycle frame cannot be utilized.
Further, the battery itself is accommodated in the battery case when putting it into a distribution channel, or setting it into a recharger such as a battery station. Accordingly, it is desirable to reduce the number and size of projections on the battery case and to reduce the weight of the battery case accommodating the battery.
In the above device, however, the clamp mechanism provided on the battery case is a projection, causing inconvenience in handling the battery, and also adding weight.
It is accordingly an object of the present invention to provide a battery mounting structure which can securely and easily detachably hold a battery to a bicycle frame without adding excessive weight.
In accordance with the present invention, a battery mounting structure in a powerassisted bicycle detachably secures a battery mounted on a bicycle frame. The battery mounting structure includes a battery holder fixed to a seat post forming a part of the bicycle frame on one of the front and rear sides of the seat post. The battery holder includes at least a bottom plate portion for receiving the battery; a buckle provided on the other of the front and rear sides of the seat post and pivotably supported to the seat post by a lateral pivot shaft; and a stop ring for locking the battery received in the bottom plate portion of the battery holder in cooperation with pivotal movement of the buckle.
With this configuration, the battery can be securely and easily detachably held to the bicycle frame without the provision of any projections such as a clamp mechanism. This reduces the weight of the mounting structure.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.